Learn how to fill a hub with oil in 3 easy steps.
3 Steps to Filling a Hub with Oil on a Semi-Trailer.

FIRST: Check the oil level.
Check to see if the oil level is touching the Full line.
If it is, you do not need to add oil.

STEP #1: Remove the drain plug.
The hub shown in our video has a drain plug.
On some hubs, you’ll remove the red plug on the front of the hub to add oil.

STEP #2: Add the oil.
- Using 75w 90 gear oil, slowly add the oil until it touches the Full mark on the hub cap. This can take a while, depending on the size of the hubcap.
- After filling the hubcap to the Fill mark, give it a couple of minutes, and recheck the level to ensure the oil has not dropped below the Full mark.
- If needed, add more oil until the oil stays at the Full mark.

STEP #3: Install drain plug.
Install the drain plug back onto the hub.
And that’s all you do to fill a hub with oil. It’s just that easy!

I’m Larry Anders.
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